f(x)=sin(2x+π/3)+sin(2x-π/3)+2cos2x-1
=1/2sin2x+√3/2cos2x+1/2sin2x-√3/2cos2x+2cos2x-1
=sin2x+2cos2x-1
=√5sin(2x+a)-1 (tana=2)
最小正周期=2π/2=π
f(x)=sin(2x+π/3)+sin(2x-π/3)+2cos2x-1
=1/2sin2x+√3/2cos2x+1/2sin2x-√3/2cos2x+2cos2x-1
=sin2x+2cos2x-1
=√5sin(2x+a)-1 (tana=2)
最小正周期=2π/2=π